Additive manufacturing, topology optimization of thermoelectric generators, and beyond: a comprehensive review on pioneering thermoelectric conversion for a sustainable future

Abstract

Thermoelectric generators (TEGs) offer a promising route for sustainable energy by converting waste heat directly into electricity, addressing critical global energy efficiency challenges. However, traditional fabrication limits TEG design complexity and application scope. This comprehensive review explores the pioneering integration of additive manufacturing (AM), particularly Direct Ink Writing (DIW), and topology optimization to overcome these limitations and enhance TEG performance. We review fundamental thermoelectric principles, material advancements (with a focus on Cu2Se), TEG design strategies (planar, lateral, vertical), simulation techniques (FEM), and AM fabrication processes. Key findings highlight AM’s ability to create complex, shape-conformable TEGs adaptable to diverse heat sources, minimizing material waste, which goes beyond previous efforts in the literature. Topology optimization significantly improves material distribution and efficiency, with studies showing optimized leg shapes yielding performance gains (e.g., hourglass shapes improving efficiency > 70 % over cylindrical). AM techniques like DIW enable high-performance materials, with 3D-printed Cu2-xSe achieving zT = 1.2 at 1000 K and printed BixSbxTex reaching efficiencies of 8.7 % (ΔT = 236 °C). While DIW offers simplicity and flexibility, its limitations and challenges include achieving high density and controlling microstructure. This review concludes that the combination of AM and topology optimization offers a transformative approach to designing and manufacturing highly efficient, customizable TEGs—key to advancing sustainable energy harvesting technologies. Future work should focus on novel printable materials, multi-material printing, and enhanced simulation models.